Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Biology 207 Biology of Cancer Lecture 21 and 22: “Cancer Treatments” Spring 2004 Readings: King Chap. 13; Breast cancer microarrays (figures): http://genome-www.stanford.edu/breast_cancer/sbcmp/figures.shtml from article by Perou et al. (1999) Proceedings of the National Academy of Sciences 96:9212-9217 available from JSTOR, Milne library. Outline: 1. Overview of cancer treatments 2. Cancer specific and stage-specific treatments 3. Advances: surgery, radiation treatments 4. Chemotherapy 5. Individualized treatments/microarrays Lecture: “Cancer Treatments” 1. Overview of cancer treatments Major treatment approaches surgery radiation therapy chemotherapy bone marrow transplant hormone therapy Cancer in situ: surgery, follow-up radiation or chemotherapy? Larger in situ tumors: surgery + radiation or chemotherapy Metastatic cancer: surgery + chemotherapy 1 2. Cancer-specific and stage-specific treatments Rationale: Each cancer type is different and may respond to different treatments; cancer is diagnosed at various stages in different individuals. Thus, it makes sense to have different treatment options for each cancer. examples: bone marrow transplant: leukemias radiation: cervical, esophageal, oral cancers chemotherapy: Burkitt’s lymphoma, Hodgkin’s lymphoma, Acute Lymphocytic Leukemia, testicular cancer hormone-based treatments: organs that produce or receive hormonal signals: tamoxifen (anti-estrogen)--breast cancer; anti-androgen therapies--prostate cancer 3. Advances: surgery, radiation treatments Advances in surgery better imaging to locate tumors less drastic surgeries: lumpectomy reconstruction new ways to determine if cancer was removed shrink tumors before surgery Advances in radiation treatments specialized machines treat localized regions implant options localized treatment reduces toxic side effects different particles used in treatments better calculations of radiation doses received by tissues 2 4. Chemotherapy Questions/Issues to be considered: How do chemotherapeutic drugs work (major classes)? Toxicity/side effects Drug resistance Combination therapies Sources of new drugs Drug testing/clinical trials MAJOR CLASSES OF CHEMOTHERAPEUTIC DRUGS 1. Antimetabolites interfere with DNA synthesis. examples: Methotrexate, fluorouracil, hydroxyurea 2. DNA damaging agents: --alkylating agents --inhibitors of DNA enzymes examples: nitrogen mustard, cisplatin, etoposide 3. Plant products that disrupt cell division examples: vinblastine, taxol How do these drugs kill the cancer cells? By “starving” them of raw materials for copying DNA. OR 2. By damaging their DNA (or not repairing damage) and triggering apoptosis (cell death). OR 3. By halting cell division. Why don’t the drugs kill normal cells? Most normal cells don’t divide frequently. Normal cells that divide frequently are subject to the chemicals, esp. blood cells, intestinal epithelial cells Toxic side effects due to killing of these normal cells intestinal cells: nausea, vomiting, diarrhea blood cells: anemia, lack of blood clotting, immunosuppression 3 Thus drug doses constantly adjusted to balance cancer cell killing and toxicity. Drug resistance--When cancer cells become altered so they no longer respond to the drug. Combination therapies--Use of two or three different drugs at the same time to minimize the likelihood of drug resistance. Adjuvant chemotherapy--Refers to situations when chemotherapy is used along with some other therapy (surgery or radiation therapy) Screening for new drugs 5. Individualized treatments/microarrays Pretesting tumors for drugs Microarray technologies Clinical trials 4